1. Field of the Invention
This invention relates generally to an externally non-conductive hose assembly made up of a hollow cylindrical member and coupling means. This invention further relates to a method of mechanically connecting and sealing the hollow cylindrical member to coupling means. The subject hose assembly is a reinforced hose assembly of the type particularly well adapted for carrying fluids (i.e., fuels, hydraulic oil, brake fluids, etc.) and other aggressive or degrading fluids.
2. Description of the Related Art
Hose assemblies for carrying machinery or vehicle fluids are known. These assemblies, in vehicle or automotive applications, are typically routed through engine compartments that reach temperatures ranging from -40.degree. F. to 400.degree. F. and carry fluids that have the potential to chemically erode, swell or otherwise degrade the interior of the hose assemblies. Therefore, these assemblies, by necessity, have to be resistant to thermal and chemical degradation. Moreover, these hose assemblies need to resist kinking during installation, use and service. Hose assemblies which include an inner Teflon.RTM. tube or cylindrical member surrounded by loosely to tightly wound metallic braid have been found to provide these necessary physical characteristics. However, the danger exists that the buildup of electricity in a piece of machinery or equipment or in the engine compartment itself may cause premature failure of such assemblies by discharging current along the conductive path formed by the end fittings and the metallic braid. Accordingly, it is common practice to provide, in the case of automobiles, such engine compartments with ground straps that conduct electricity to the vehicle frame. Yet, on occasion, typically following vehicle service or maintenance (which necessitates the disconnection of such ground straps) manual reconnection of these straps fails to occur. As a result, such hose assemblies serve as conductive paths to ground within the engine compartment causing the reinforcing layer or braid to generate heat. The generated heat, over time, serves to melt or soften the Teflon.RTM. tube or member resulting in premature leakage. In automobile fuel lines, such leakage could result in engine fires.
It is therefore an object of the present invention to provide a hose assembly that is externally non-conductive.
It is a further object of the present invention to provide a method of mechanically connecting and sealing a hollow cylindrical member to coupling means thereby providing such an externally non-conductive hose assembly.